Continuous zipper sewing apparatus and method



CONTINUOUS ZIPPER SEWING APPARATUS AND METHOD Filed July 24, 1964 N 1966 J- L- ROCKERATH ETAL 5 Sheets-Sheet. 1

1966 J. L. ROCKERATH ETAL 3,

CONTINUOUS ZIPPER SEWING APPARATUS AND METHOD Filed July 24, 1964 5 Sheets-Sheet 2 mum/0m 2/ I F/ Jam Lfioc/femfh Jam 5 G0 pen Ham/d J (h/66A By fhe/r affomeys K MMMM 3,286,669 CONTINUOUS ZIPPER SEWING APPARATUS AND METHOD Filed July 24, 1964 N 1966 J. ROCKERATH ETAL 5 Sheets-Sheet 3 //7 1 60 20/5 John LROC/rem/h Jam E Gap Jen Ham/d J Sch/66 By fhe/r af/omeys Unitcd States Patent John L. Rockerath, Utica, John E. Goppert, New Hartford, and Harold J. Schreck, Utica, N.Y., assignors to Jet Sew Inc., Barneveld, N.Y., a corporation of New York Filed July 24, 1964, Ser. No. 384,967 3 Claims. (Cl. 112265) This invention relates to continuous zipper sewing apparatus and method, and more particularly to such apparatus and method as associated in a zipper setting setting machine to install or set continuous or intermittent lengths of zippers in concealed seams. Continuous is understood to refer to lengthy zippers such as are used for closures in, for example, equipment such as sleeping bags. Each zipper, continuous or intermittent, has the usual tab and slider to connect staggered sets of teeth.

The present invention is an improvement upon US. Patent 3,016,028 of January 9, 1962, granted to Harold J. Schreck and John L. Rockerath, for Sewing Machine and Method. The invention is easily used in connection with the disclosures of this patent, but can be adapted to other machines.

In a sewing machine, a presser foot ordinarily is used to help form stitches, that is, to sew. So long as material passing through the stitch point is relatively uniform, this construction is satisfactory, for some flexibility or degree of yield is usually designed into the presser foot system. Sewing in of a zipper, on the other hand, presents difiiculties not compensated for by the ordinary design. The bulk of a zipper slider and tab cannot pass the usual presser foot, throat plate and feed dog combination. The Schreck and Rockerath Patent 3,016,028 solved this problem by eliminating the feed dogs; providing a channel for the zipper and its elements; and installing a non-loaded, floating presser foot (that is to say, a presser foot which rides very lightly on material thereunder, without exerting positive pressure, and serves primarily to prevent the material from flagging or following in the direction of withdrawing needles, during sewing). This structure, in effect, added a second dimension to the machine, which provided additional vertical clearance for zipper sliders and tabs.

With use of the machine and method of the cited Schreck and Rockerath patent it has been observed occasionally that friction on one side of the zipper fabric tends to produce a wavy effect in the fabric as finished. Even the non-loaded or floating presser foot apparently forces more fabric material than zipper into the stitch line. The present invention positively prevents this uneven distribution; precludes occurence of the undesirable wavy effect in the fabric; and ensures free passage of tobe-sewed fabric through the machine.

Additional difficulties have also been experienced with zipper setting machines such as that disclosed in the Schreck and Rockerath Patent 3,016,028. In particular, puckering of fabric has occurred; and zipper sliders have jiggled up and down in their path, causing irregular motion of tapes. Flagging has occurred. The machine of the 3,016,028 patent has lacked means adequate to hold down the zipper tapes as they pass through the stitch points. These difliculties lead to non-uniform zipper settings. Briefly, then, the usual presser foot arrangment is unsatisfactory, and while the cited patented apparatus is more satisfactory in some respects, it is still imperfect in other respects.

It is an object of the present invention to provide an improved zipper setting machine that overcomes the above recited drawbacks and difliculties experienced with known zipper setting machines.

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It is another object of the present invention to provide a machine that rapidly, accurately sets continuous zippers in concealed or placket-type seams and butt seams.

Other objects will become apparent as the specification progresses.

The invention employs mechanism to feed to-be-sewed fabric and zipper-bearing tapes through the machine, devices to control tension on the tapes as they are fed through the machine, in combination with means which eliminate a presser foot and which means are disposed adjacent the stitching area to mainatin the tapes flat as they move through the stiching area, and apparatus associated with the means which maintain the tapes flat to fold the to-be-sewed fabric into looped strips for seaming.

With reference to the drawing generally:

FIGURE 1 is a plan view of an embodiment of the invention adapted to make a placket seam, showing both left and right turn down folders in operating position. A zipper is shown passing under the turn down folders. The overlying and larger looped strip is illustrated with relation to the smaller looped strip created by the right hand turn down folder. The dotted lines represent the successive points of stitching of the needles.

FIGURE 2 is a plan view of the left hand turn down folder of the embodiment of FIG. 1, showing the relation thereof to the left hand needle.

FIGURE 3 is a view of the bottom of the element of FIG. 2, showing the left hand stripper member. The dash lines at the needle end of the folder represent the lower thickness of fabric passing through the convolutions of the folder. This portion of the fabric has been cut away so as to illustrate the relationship of the diverter and the stripper. The dash line at the input end represents the same fabric thickness as just described, as it rests on the top side of the folder before being folded into a loop.

FIGURE 4 is an inverted front view of the element of FIG. 2 showing fabric inserted into the convolutions of the turn down folder.

FIGURE 5 is a plan view of the right hand turn down folder of the embodiment of FIG. 1, showing the relation thereof to the right hand needle.

FIGURE 6 is a view of the bottom of the element of FIG. 5.

FIGURE 7 is a front view of the element of FIG. 5 with the right hand stitch line indicated by the vertical dot dash line, and the zipper and tapes being indicated. The mounting bracket for the element is also shown, attaching the element to the throat plate of the machine. The irregular dot and dash line out-lines fabric being drawn through the machine.

FIGURE 8 i a front view of both left and right turn down elements of the embodiment of FIG. 1 shown in relation to the zipper and the needle positions. The vertical dot and dash lines mark the paths of needle recipro-. cation.

FIGURE 9 is a schematic side view of the left hand turn down element'shown in FIG. 4. The vertical dot and dash line marks the path of needle reciprocation.

FIGURE 10 is an elevation view from the left end of the embodiment of FIG. 1, showing the tension control means, the draw roller feed mechanism, the finger guard and it control mechanism.

FIGURE 11 is an elevation view from the rear, taken along line 11-11 of FIG. 10, showing the finger guard and its control mechanism, the guard being in the down or protective position.

The two needle sewing machine of the Patent 3,016,028 will be used as the basis for the following description.

The present invention can be used to make butt type scams or placket type seams. The drawings are exemplary of the construction used for placket or concealed seams. No limitation to placket seams is intended.

There is a throat plate 20 having a channel 22 to admit and facilitate ready passage of zipper sliders under the stitch points. Strippers 4, 9 and 9 maintain zipper tapes 12 and 13, respectively, flat and non-flagging. The stripper 4 (c.f. FIG. 3 and FIG. 1) is attached to the folder 1 and serves to check untoward movements of tape thereunder. The under portion 9 of the convolution 7 of the folder 6, and the leading corner 9 of this folder provide a two element stripper for folder 6. This stripper also serves to check untoward movements of tape thereunder. All stripper structure is thus disposed between the fabric strips and the tape strips. It will be observed that these strippers maintain control of the tapes. until quite close to the stitch points of needles 16 and 17. On the other hand, the strippers do not bring positive pressure to bear on the tapes, as does a presser foot. They simply resist untoward movement of the tapes, which movement would deteriorate into flagging if left unchecked.

Nor do the strippers control the tension of the tapes going through the machine. The draw roller mechanism 24 and the needle feed, taught by Patent 3,016,028 provide the feeding motion for both the tapes and the fabric being stitched together. A variable speed drive 25, forward mounted near a corner of the machine 3-1, a shaft 27 connected to the drive 25 at a point somewhat in front of the bed and stitching area, a brake mechanism 26 for the shaft 27, and a tape guide assembly including supply reel 30, H-frame 29, and roller 28, adjacent to the visible end of the shaft 27, are used to control the tension on the tapes as they move through the machine. These several mechanisms can be cooperatively adjusted to set tension, or they can be adjustedindependently and used independently. This construction thus provides a wide range of useful adjustability of tape tension.

A further observation should be made about the strippers: they are used to separate to-be-sewed fabric strips from the tapes, up to the points where stitching occurs. The foregoing features of construction permit the elimination of the usual presser foot, providing flexibility and improved quality to the performance of the machine.

Left hand turn down folder 1 and right hand turn down folder 6 serve to guide and fold fabric strips to be sewed to tapes 12 and .13, respectively. The folders are adjustably mounted to the usual machine base (shown outlined in FIG. 1) by means of brackets and 10. Reverse shaped folders may be used to reverse the looped strip relationship. The disclosure is not limited to the left and right positions of the turn down folders as illustrated.

Turn down folder 1 is designed with convolutions 2 adapted to form a zipper seam overlying loop 3 in the form of looped strip of fabric 14 having under portion 14'. Loop diverter 21 ensures that the loop 3 will remain looped as it is drawn into looped strip 14 to cover the over the zipper 11 and stitch line 19. The folder 6 has a folder convolution 7 to form the looped strip of fabric 15 having under portion 15. Stitch line 18 marks the point of atachment of looped strip 14 to the zipper tape 12. The end product, seen in FIG. 1, shows the relation of zipper 11, looped strip 14 overlying looped strip 15, and thus also concealing stitch line 19 connecting strip 15 to the zipper tape 13.

The left hand turn down folder 1 is mounted to slightly overlie the right hand turn down folder 6. Folder 1 is also mounted about A; of an inch in advance (toward the stitch point) of folder 6. Heretofore, folding mechanisms have been disposed behind the presser foot. By eliminating the presser foot the inventors have been able to move the folders right up to the stitch points and thereby provide improved sewing conditions. With reference to FIG. '8 it will be seen that, even with the folders placed in overlying relationship, -a certain fixed vertical clearance or space 11 exists above the zipper. This is an essential feature of the invention, for it enables the bulky zipper l sliders to slip right past the folders and through the stitch points with no drag or tape-dislodging friction. The provision of this space results directly from elimination of the presser foot.

As a precaution to ensure the safety of the operators fingers, a transparent finger guard 33 is installed in front of the needles and above the folders. This is a rigid guard designed to drop into protective position as soon as fabric or tapes go through or under the folders. A light source casts a light beam into photo electric cell 34 until the passing of fabric or tapes breaks the beam. At such moment, the cell 34 triggers solenoid 32 so that the guard 33 drops into place. When the beam passage is restored, by clearing the fabric or tapes away, for example, the solenoid is caused'to withdraw the guard upward, out of the way. It will be observed that this guard in no way presses upon the fabric, even in its down or finger protecting position. It serves only as a finger guard, and in no manner acts upon the fabric or tapes.

The structural details of the invention having been set forth above, a method of operating the machine will now be described. To-be-sewed fabric strips and Zipper-bearing tapes are fed, under controlled tension, through a sewing machine. At the same time the tapes are maintained flat, without a presser foot, as they move through the machine; the fabric strips are folded into looped strips preparatory to sewing; and the strips and the tapes are then stitched together.

Tapes 12 and 13 are drawn through the stitch points primarily by the pull or draw feed mechanism of the Schreck and Rockerath Patent 3,016,028. The strippers 4, 9 and 9 prevent flagging of the tapes during stitching. Refined control of the tension on the tapes is obtained through the mechanisms disclosed in said patent, referred to above and shown in FIG. 10 of the drawings of the present application. While the present invention is disclosed with reference to continuous zippers it can be used to stitch in intermittent zippers. In either case bulky Zipper sliders readily move past the stitching area via the vertical clearance or space 11' and channnel 22 in throat plate 20 of the present invention. Although the sliders easily pass, they are, at the same time, prevented from jiggling, and thus from dislodging the tapes, by the restraint placed upon the'tapes 12 and 13 by the strippers.

As the tapes advance through the machine the operator guides to-be-sewed-fabric strips, see FIG. 8, into the turn down folders I and 6. The drawings show the feeding of these strips to be at right angles to the feed of the tapes, see FIG. 2 reference character 23, in particular. This is a practically convenient angle, but no limitation to the same is intended. The larger, or left hand turn down folder, 1, overlies and is mounted in advance of the smaller, or right hand turn down folder, 2, so that as the fabric strip goes through folder 1 it is raised slightly by loop diverter 21, with respect to the strip going through folder 6, and creates an overlap for concealment, without the fabric engaging with the right hand needle 17. As a fabric strip goes through folder 1 it is also caught up in the convolutions 2 and folded into loop 3. Loop diverter 21 also maintains the loop as is and casts it off as looped strip 14 onto looped strip 15 as the material moves forward out of the folders. The folder 6 folds a fabric strip passing therethrough into looped strip 15'.

Initially, an operator will haveto feed the fabric strips as well as guide them, into the folders. Once the needles take hold of the fabric strips, the operator need only guide them into the folders.

. It will be seen that the tape strips 12 and 13'are adequately restrained from untoward motion, by the strippers 4, 9 and 9'. Consequently, the tapes provide a uniformly steady medium that is used to help form high quality stitches.

The transparent 'finger guard 33 is designed to move into place, and withdraw therefrom, automatically, depending for its motion upon whether fabric or tapes arebeing fed through the machine. Operator control of this device is manual to that extent only. This construction ensures a high degree of safety for the operators fingers. It provides this safety without need for operator attention.

It is apparent from the drawings, particularly FIG. 9, that the folders maintain the fabric strips relatively high above the level of the tapes. Some of the practical considerations leading to this construction are the needs to provide both some underneath clearance for the folder structure, and a relatively uniform surface so that the operator can guide fabric strips.

It is reiterated that by combining the mounting of the folders forward of their heretofore conventional position (behind the presser foot, which device is eliminated here), and the mounting of strippers between fabric and tapes the inventors have been able to overcome the previously experienced difficulties of wavy irregularities; puckering of fabric as finished; and jiggling of the sliders.

The present invention is not to be understood as being intended for use only with the disclosures of the Schreck and Rockerath Patent 3,016,028. Such adaptations or changes in the present invention as workers normally skilled in the art may evolve are to be understood as coming within the ambit of the preceding specification and the claims that follow.

What is claimed is: 1. A two needle machine for sewing continuous zippers into fabric comprising draw roller mechanism to move to-be-sewed fabric and zipper-bearing tapes through the machine,

differential means mounted forward relatively to the needles to cooperate with said draw roller mechanism to maintain the tapes taut as they move through the machine, including variable speed drive apparatus, brake devices therewith associated, and a tape guide assembly,

a turn down folder disposed above one stitch point, to

fold fabric into a looped strip of fabric for seaming,

a larger turn down folder disposed above the other stitch point, having plural convolutions to fold fabric into a larger looped strip of fabric for seaming, and a loop diverter within said convolutions, said larger turn down folder overlying the smaller turn down folder to place the larger looped strip in overlying relation to the zipper, conceal-ing the same, and there being a fixed space directly above the line of travel of the zipper to facilitate free passage of zipper sliders between the folders, without dislodging the tapes, stripper elements one adjacent each needle and stitch point, disposed on each turn down folder and spaced apart from each other to facilitate passage of zipper sliders therebetween, and simultaneously maintain the tapes flat as they move close to the stitch points, a throat plate adjoining the stitch points, having a channel beneath the stripper elements to further facilitate passage of zipper sliders through the stitch point-s,

and a non-pressing finger \guard adjacent the needles, above the folders, and movable between protective and withdrawn positions.

2. Apparatus as in claim 1 in which the larger turn down folder is spaced forward of the smaller turn down folder; whereby the larger looped strip is guided into zipper seam overlying and concealing position as the zipper and fabric are stitched together.

3. A method of sewing continuous zippers into fabric comprising drawing to-be-sewed fabric and zipperbearing tapes, under controlled tension, through a two needle sewing machine,

in combination with the steps of separating each tape from its associated fabric strip up to the points of stitching by insert-ing a stripper member between each tape and associated fabric strip,

maintaining each tape flat, with the appropriate stripper, as the tape moves through its stitch point, thus preventing slider jiggle and flagging of the fabric,

guiding one fabric strip at an angle to the tape feed into a turn down folder,

guiding the other fabric strip at an angle to the tape feed into a smaller turn down folder,

passing zipper sliders, unobstructed and between the strippers, through the stitching area,

folding the fabric strip in the smaller turn down folder to form a looped strip, and releasing the looped strip from said folder,

simultaneously folding the fabric strip in the larger turn down folder into a larger looped strip and releasing the same just subsequent to release of the smaller, looped strip, so that the larger, looped strip overlies the smaller, looped strip, concealing the zipper,

and stitching the fabric strips and tapes together, using the tapes to facilitate the forming of the stitches.

References Cited by the Examiner UNITED STATES PATENTS 2,079,834 5/1937 Blumenkrantz 1l22 2,151,346 3/1939 Devoe 112-2 2,166,350 7/ 19 39 Freshman 112r2 2,977,904 4/1961 Carmen 112-141 X 3,006,302 210/1961 McNamara 112-265 3,016,028 1/1962 Schreck et al. 112-2 3,085,525 4/ 1963 Rosern'an et al. 112--2 JORDAN FRANKLIN, Primary Examiner.

J. R. BOLER, Assistant Examiner. 

1. A TWO NEEDLE MACHINE FOR SEWING CONTINUOUS ZIPPERS INTO FABRIC COMPRISING DRAW ROLLER MECHANISM TO MOVE TO-BE-SEWED FABRIC AND ZIPPER-BEARING TAPES THROUGH THE MACHINE, DIFFERENTIAL MEANS MOUNTED FORWARD RELATIVELY TO THE NEEDLES TO COOPERATE WITH SAID DRAW ROLLER MECHANISM TO MAINTAIN THE TAPES TAUT AS THEY MOVE THROUGH THE MACHINE, INCLUDING VARIABLE SPEED DRIVE APPARATUS, BRAKE DEVICES THEREWITH ASSOCIATED, AND A TAPE GUIDE ASSEMBLY, A TURN DOWN FOLDER DISPOSED ABOVE ONE STITCH POINT, TO FOLD FABRIC INTO A LOOPED STRIP OF FABRIC FOR SEAMING, A LARGER TURN DOWN FOLDER DISPOSED ABOVE THE OTHER STITCH POINT, HAVING PLURAL CONVOLUTIONS TO FOLD FABRIC INTO A LARGER LOOPED STRIP OF FABRIC FOR SEAMING, AND A LOOP DIVERTER WITHIN SAID CONVOLUTIONS, SAID LARGER TURN DOWN FOLDER OVERLYING THE SMALLER TURN DOWN FOLDER TO PLACE THE LARGER LOOPED STRIP IN OVERLYING RELATION TO THE ZIPPER, CONCEALING THE SAME, AND THERE BEING A FIXED SPACE DIRECTLY ABOVE THE LINE OF TRAVEL OF THE ZIPPER TO FACILITATE FREE PASSAGE OF ZIPPER SLIDERS BETWEEN THE FOLDERS, WITHOUT DISLODGING THE TAPES, 